KiwiNZ: The best way to deal with muppets is to take a defensive or advanced driver course.
Totally agree that such courses would be valuable; the problem is they don't appear to be available in some areas. For example, I'm keen on doing such a course and tried to find one in my area (Palmerston North/Manawatu). Every single course available was focused on learner drivers - ie the course that enables new drivers to reduce the period of time before getting the next stage of their licence (between restricted and full?).
I don't want that kind of course - it's mostly theory delivered by classroom learning. This is a topic I think experiential learning - as in an actual car! - is probably the most valuable. I assume the big centres have companies that provide this type of training? (Actually, it's made me think I should see if my employer can provide its employees with such training - given we employ driver trainers...)